International patent publication WO2010114806 discloses a charge-balancing system for multiple cells in a battery. The system includes multiple circuits and a control module. Each circuit includes first and second switches connected in series and an inductance having a first end connected between the first and second switches. The control module outputs control signals to control the first and second switches. A second end of the inductance of a first one of the N circuits is connected between two cells of a first pair of series-connected cells of a battery stack. The first and second switches of the first one of the N circuits are connected in parallel to the first pair of 2N series-connected cells.